How Hub and Spokes Affect Wheel Performance？
Many cyclists choose carbon wheels based solely on rim height and weight. However, what truly determines whether the wheels feel smooth and reliable over long rides are the hubs, bearings, and spokes. Especially in the last two years, terms like 45T/36T ratchet, ceramic bearings, one-piece carbon spokes, and Sapim CX-Ray flat steel spokes have appeared repeatedly. This article will clarify these points.
45T vs 36T Ratchets
How Fast Does Engagement Take, How Loud Is It?
Star ratchets transmit power through two interlocking toothed discs. All teeth bear force simultaneously, making them more resistant to high torque and less prone to slippage than traditional pawls. The number of teeth directly determines the "engagement angle":
• 36T: 360° ÷ 36 ≈ 10° engagement angle. The crank needs to be turned slightly before starting to apply force; the sound is lower-frequency and less dense, making it more reliable for long rides and gravels.
• 45T: 360° ÷ 45 ≈ 8° engagement angle, providing better responsiveness than 36T, resulting in quicker acceleration, cornering, and acceleration on technical sections; the sound is denser and more "buzzing," typical examples being the ICAN AERO50 II D91 45T.
• Higher, such as 54T ≈ 6.7°, offers even faster response but smaller teeth and higher lubrication requirements; suitable for road racing/technical gravel, but not necessarily necessary for everyday use.
The ICAN G24 SL gravel wheelset uses a D91 45T + S&S steel axle, emphasizing less dead zone on technical surfaces; the G24 SL switched from the older 6-pawl D21 to a D91 45T, resulting in an "angry bee" sound and more even torque distribution; the AERO50 II uses a 45T hybrid ratchet with approximately 8° engagement, paired with CX-Ray for all-around road use. If you prefer a more endurance gravel feel and are concerned about high-frequency maintenance, the 36T or DT 240 are more stable. The G24 SL also offers the DT240 EXP option.
Don't just assume "loudness equals speed." Loudness and engagement angle are two different things. Grease thickness, number of teeth, and hub seals all affect the sound.
Ceramic Bearings
Smooth, but Not a Panacea
Ceramic bearings typically refer to hybrid ceramic (steel rim + ceramic ball). Their advantages include low rolling resistance, high hardness, and good corrosion resistance; they are often an upgrade option for high-end gravel/road wheels. The ICAN G30 offers a D91 ceramic bearing version, emphasizing low friction and smoothness in harsh environments.
However, the actual choice depends on the scenario:
• Dry road/time trial/climbing where inertial smoothness is prioritized: Ceramic bearings are worthwhile.
• Rainy gravel/muddy roads: Bearing seals and grease are more important than "whether it's ceramic or not." S&S steel axles and ordinary industrial bearings offer better value for money as long as they are well-sealed and regularly maintained. • Ceramic wheels are more susceptible to impurities. Sand ingress can cause abnormal noises and wear. Before upgrading to ceramic wheels, confirm the hub specifications, preload, and after-sales service.
Carbon Spokes
Lightweight, Stiff, and Aerodynamic, but Don't Misunderstand as "Maintenance-Free"
A single carbon spoke can weigh only 2-5g (varies greatly depending on the design), significantly lighter than the CX-Ray's approximately 4.25-4.75g. The flat, wide airfoil cross-section offers better aerodynamic drag than round steel spokes, often saving 2-5W at speeds above 40km/h (manufacturer/third-party data varies greatly). In terms of stiffness, carbon spokes exhibit less tensile deformation and less lateral displacement during pedaling, resulting in a stronger "direct feel" for acceleration and sprinting. Laboratory samples have shown that under a 200N lateral force, the displacement of a carbon spoke wheel is approximately half that of a steel spoke under the same conditions. However, this data is greatly affected by the rim, lacing, and tension, and cannot be considered a universal conclusion for all wheelsets.
The disadvantages of carbon fiber spokes must also be clearly explained:
• Strong tensile strength in the fiber direction, but limited adjustment space after lateral bending, impact from sharp objects, or severe rim wobble; the tension of some split carbon spokes is basically fixed at the factory, unlike steel spokes which can be freely adjusted with spoke caps.
• Steel spokes are more reliable for high-impact, frequent crashes, and long-distance unmanned riding.
• The cost of replacing a single spoke, the availability of special caps, and special tools should all be inquired with the brand in advance.
Sapim CX-Ray
Why Many "All-Round Carbon Wheels" Still Use Steel Speakers
CX-Ray is made of 18/8 stainless steel, with a stamped oval midsection of 2.0−2.2×0.9−2.0 mm, approximately 4.4–4.5g per spoke (64 spokes of 260mm each weigh approximately 279g). The manufacturer claims a midsection strength of 1600N/mm², and its fatigue testing is top-tier within the Sapim system. It is compatible with standard J-bend/straight-pull hubs and uses a special flat wrench to prevent torsion. Its positioning isn't "lightest," but rather lightweight + aerodynamic + repairable:
• Flat cross-section reduces wind resistance, but not as extreme as wide carbon steel strips;
• Steel strips have slight elasticity, absorbing vibrations better than hard carbon steel strips on rough roads;
• Tension can be adjusted individually if the wheel misaligns, making it more suitable for long-distance driving, racing, and gravel runs;
• Many ICAN models, such as the AERO50 II, G30, and G24SL, use CX-Ray + Sapim Secure-Lock for vibration prevention and ease of after-sales service.
The conclusion is straightforward: for extreme weight reduction and strong acceleration, choose carbon steel strips; for comprehensive road conditions, maintainability, and long-term stability, choose CX-Ray or high-grade variable-diameter steel strips.
Tire Configuration by Target Audience
• Flat roads/all-around highways, occasional climbing: 40–50mm rim + 45T ratchet + CX-Ray + steel / S&S bearings, such as the AERO40 II / AERO50 II approach.
• Climbing-first: Low rim 30–40mm + 45T or 36T + CX-Ray, such as the G24SL.
• Gravel wide tires: 25–30mm inner width + 36T/45T (45T is more responsive on technical roads) + CX-Ray, such as the G30; use carbon fiber spokes if weight is a priority, but ensure parts are replaceable and covered by crash warranty.
• Show bikes/time trials/extreme aerodynamics: High rim + carbon fiber spokes + ceramic tires + 45T/higher ratchet, accepting higher maintenance and replacement costs.
In short
If you can hear the buzzing and feel the solid ground, go for the 45T + ceramic tires; if you're afraid of mud, long drives, or want to tune your own wheels, the 36T/45T + CX-Ray steel tires are the worry-free, high-performance solution for most people.
